1. Field of the Invention
The present invention relates to a method of manufacturing a semiconductor device, and more particularly, to a silicon-based light emitting diode (LED) including a distributed Bragg reflector (DBR).
2. Description of the Related Art
Much research has been conducted into silicon-based LEDs using silicon nano-size dots, because they are easily compatible with silicon-based photoelectronic devices and have low manufacturing costs. However, current silicon-based LEDs are not widely used in commercial applications because of their low emission efficiency and wide emission spectrum.
A DBR with a high reflectance is used in various photoelectronic devices designed for light-emission, photo detection, light modulation, and other functions. A DBR is a multi-layer mirror composed of alternating layers of two materials having different refractive indices, and reflects light using the difference between the refractive indices of the layers.
In a typical compound semiconductor LED, a doping material is injected into a DBR to achieve high emission efficiency and narrow emission spectrum. However, in a silicon-based LED using silicon nano-size dots, there is a problem indirectly doping a DBR, because the DBR is typically composed of insulating materials such as silicon oxide and silicon nitride, according to an underlying structure including an active layer. Furthermore, since a large band-gap semiconductor doping layer always has an n-type conductivity, it is very difficult to form a p-type semiconductor doping layer. Given the shortcomings of the silicon-based LED, there is a need to develop a doping layer and an LED structure for effectively injecting electrons and holes.